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 Carbon Cycle And Ecosystems (329G): People
Kristal  Verhulst's Picture
Jet Propulsion Laboratory
M/S 233-300
4800 Oak Grove Drive
Pasadena, CA 91109
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Curriculum Vitae:

Kristal Verhulst

Dr. Kristal (Kris) Verhulst is an analytical chemist by training and is interested in understanding how human activities impact tropospheric composition, chemistry, and the global carbon cycle. Dr. Verhulst has 10 years of experience measuring atmospheric trace gas species, pollutants and greenhouse gases (GHGs) using cavity-ringdown spectroscopy (CRDS) and/or gas chromatography/mass spectrometry (GC/MS) techniques. She currently manages a GHG surface network in Los Angeles as part of the Megacity Carbon Project and has managed data collection, processing, and QA/QC for the CRDS analyzers, including development of calibration/validation plans. She is also interested in remote sensing of point source greenhouse gas emitters as well as remote sensing applications and information systems. As Co-I on the NASA Develop LA Health and Air Quality project, Dr. Verhulst pioneered Vista-LA, a novel Geographic Information System (GIS)-based applications tool for sectoral attribution of GHG emissions in the LA Megacity. More recently, the tool has been adopted and linked with remotely sensed data for flight planning and data analysis for the HyTES and AVIRIS remote sensing instruments.

At UC Irvine, Dr. Verhulst was a member of the West Antarctic Ice Sheet-Divide (WAIS-D) Science Team. Her work involved reconstructing atmospheric trends for trace gases relevant to the global carbon cycle and biogeochemical cycling. She developed analytical methods for the extracting ultra-trace gases (i.e. parts per trillion level gases in the atmosphere) from polar ice cores and firn air (the interstitial air trapped in snow and porous ice) from Greenland and Antarctica.

  • Ph.D. Earth System Science, University of California-Irvine (2014)
  • M.S. Earth System Science, University of California-Irvine (2010)
  • B.S. Chemistry, University of California-Irvine (2008)

Research Interests
  • Understanding how human activities impact air quality, atmospheric chemistry, and the global carbon cycle.
  • Utilizing in situ and remote sensing measurements to understand atmospheric change, long-term trends, and surface fluxes of trace gases.
  • Remote sensing of point source greenhouse gas emitters using aircraft- and satellite-based remote sensing technologies.
  • Remote sensing applications.


Megacities Carbon Project Icon Megacities Carbon Project
The Megacities Carbon Project is being established for the megacities of Los Angeles and Paris.

JIFRESSE is a scientific collaboration between UCLA and JPL to improve understanding and to develop future projections about global climate change.

OCO-2 - Orbiting Carbon Observatory Icon OCO-2 - Orbiting Carbon Observatory
The Orbiting Carbon Observatory-2 (OCO-2) is a mission designed to make precise, time-dependent global measurements of atmospheric carbon dioxide (CO2) from an Earth orbiting satellite.

Professional Experience
  • University of California, Los Angeles (2017-present)
    • Assistant Researcher, Joint Institute for Regional Earth System Science and Engineering (JIFRESSE) (2017-present)
  • California Institute of Technology (2014 to 2016)
    • Postdoctoral Scholar (2014-2016)
  • University of California, Irvine (2006-2014)
    • Graduate Student Researcher (2008-2014)
    • Teaching Assstant (2010-2013)
    • Junior Specialist (2008-2009)
    • National Science Foundation REU Fellow (2007)

Selected Awards
  • NASA/UCSD Cal Space Fellowship (2014)
  • Ralph J. and Carol M. Cicerone Fellowship (2014)
  • American Geophysical Union, Outstanding Student Paper (2012)
  • UC Irvine Faculty Mentor Program Fellowship (2010-2011)
  • ESS/IGPP Symposium, Outstanding Research Presentation, (2009)
  • Phi Lambda Upsilon and Cum laude Honors in Chemistry, UC Irvine (2008)
  • National Science Foundation, REU Fellow (2007)
  • Lockheed Martin Aeronautics Scholarship (2006)

Selected Publications
  1. Verhulst, K. R., A. Karion, J. Kim, P. K. Salameh, R. F. Keeling, S. Newman, J. Miller, C. Sloop, T. Pongetti, P. Rao, C. Wong, F. M. Hopkins, V. Yadav, R. F. Weiss, R. M. Duren, and C. E. Miller (2016). In Situ Carbon Dioxide and Methane Measurements from the Los Angeles Megacity Carbon Project, 1: Calibration, Urban Enhancements, and Uncertainty Estimates, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-850, (in review).
  2. Viatte, C., T. Lauvaux, J. K. Hedelius, H. Parker, J. Chen, T. Jones, J. E. Franklin, A. J. Deng, B. Gaudet, K. Verhulst, R. Duren, D. Wunch, C. Roehl M. K. Dubey, S. Wofsy, and P. O. Wennberg (2016) Methane emissions from dairies in the Los Angeles Basin, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-281, (in review).
  3. M. R. Nicewonger, K. R. Verhulst, M. Aydin, and E. S. Saltzman (2016). Preindustrial atmospheric ethane levels inferred from polar ice cores: A constraint on the geologic sources of atmospheric ethane and methane. Geophys. Res. Lett., 43, 214-221, doi: 10.1002/2015GL066854.
  4. M. Aydin, J. E. Campbell, T. J. Fudge, K. M. Cuffey, M. R. Nicewonger, K. R. Verhulst, and E. S. Saltzman (2016). Changes in atmospheric carbonyl sulfide over the last 54,000 years inferred from measurements in Antarctic ice cores. J. Geophys. Res. Atmos., 121, doi: 0.1002/2015JD024235.
  5. M. Aydin, T. J. Fudge, K. R. Verhulst, M. R. Nicewonger, E. D. Waddington, and E. S. Saltzman (2014). Carbonyl sulfide hydrolysis in Antarctic ice cores and an atmospheric history for the last 8,000 years. J. Geophys. Res.: Atmospheres, 119, doi: 10.1002/2014JD021618.
  6. Verhulst, K. R., M. Aydin, and E.S. Saltzman (2013). Methyl chloride variability in the Taylor Dome ice core during the Holocene. J. Geophys. Res. Atmos., 118, 1-11, doi:10.1002/2013JD020197.
  7. M. Aydin, K. R. Verhulst, E. S. Saltzman, S. A. Montzka, D. R. Blake, Q. Tang, and M. J. Prather (2011). 20th century ethane variability from polar firn air and implications for the methane budget. Nature, 476, 198-201, doi:10.1038/nature10352
  8. S. A. Montzka, L. Kuijpers, M. O. Battle, M. Aydin, K. R. Verhulst, E. S. Saltzman, and D. W. Fahey (2010). Recent increases in global HFC-23 emissions. Geophys. Res. Lett., 37(L02808), doi:10.1029/2009GL041195.
  9. M. Aydin, S. B. Montzka, M. O. Battle, M. Williams, W. J. DeBruyn, K. R. Verhulst, et al. (2010). Post-coring entrapment of modern air in polar ice: Evidence from CFC-12 measurements in Antarctic firn air and shallow ice cores. Atmos. Chem. Phys., 10 (5135-5144), doi: 10.5194/acp-10-5135-2010.
  10. E. S. Saltzman, M. Aydin, K. R. Verhulst, B. Gun, and M. Williams (2009). Methyl chloride in a deep ice core from Siple Dome, Antarctica. Geophys. Res Lett., 36 (LO3822), doi: 10.1029/2008GLO36266.

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